An S-scheme CeO2/ foveolate g-C3N4 composite with horseradish peroxidase activity for photo-enzyme synergistic catalytic degradation of phenanthrene

Nanozyme technology is a relatively new technology that has shown promising applications in the removal of water pollutants. This study utilized a CeO2/foveolate g-C3N4 (CeO2/FCN) composite with S-scheme heterojunction to achieve efficient removal of Phenanthrene (PHE) through a combination of photocatalytic and enzymatic reactions. The S-scheme heterojunction was effective in inhibiting the recombination of photogenerated electron hole pairs, which promoted the generation of·OH and·O2-. Additionally, activated H2O2 enables Ce to achieve redox cycle reaction and generate more·OH for catalytic degradation, effectively improving the concentration of active species and promoting the photo-enzyme synergistic catalytic performance. The experimental results showed that PHE degradation efficiency of CeO2/FCN composite could reach 96.6% in 60 min. Furthermore, the photo-enzyme synergistic catalytic mechanism of CeO2/FCN composite and the possible intermediates generated in the degradation process were studied. The highly toxic PHE was converted into non-toxic green degradation products, providing an effective method for the photo-enzyme synergistic catalytic degradation of PAHs.